This invention pertains to flangeless winding cores for magnetic tape, adapted for stacking with their surfaces in contact and the tapes wound thereabout in supporting contact.
The recording of sound on magnetic tape and the packaging and marketing of such tape recordings has become a large-scale industry incorporating many mass production techniques. Standardized winding cores used in transporting the tapes and handling the tapes during processing are generally adapted to take advantage of such techniques.
Two factors are of particular importance with respect to such techniques. First, the capability to stack such cores with tape wound therearound, but without intervening support material between the tape on adjacent cores, permits increased efficiency in transporting and handling the cores and tape. Secondly, the expensive and sophisticated machinery utilized in processing the tape in large part is adapted to employ holding devices for the cores which create a significant design requirement. Briefly, to accommodate stacking efficiency, the core should generally have a height approximately equal to the width of the tape wound therearound. On the other hand, to accommodate processing with the existing expensive machinery, a greater height than the width of many of the tape sizes, is required.
Ender et al, U.S. Pat. No. 4,081,151 addresses these somewhat contradictory requirements by providing deformations which alternately rise on opposite (top and bottom) sides of a core. These deformations take a rather complex shape permitting interlocking of a deformation rising from the top side of a lower core with the recessed underside of a deformation rising from the top side of an upper core. The height of such cores, apart from the projections, may then generally be about the same as the width of the tape. With respect to such height, Ender discloses projections extending about one half of that height beyond the part of the core having that height; however, cores along the lines of that in Ender, have been employed with projections larger than this ratio. Concerning another aspect, spindle indentations normally required in the winding cores, as a result of the other aspects of the design in Ender, are located along the deformations, and follow an alternating pattern resulting from the alternating pattern of the deformations.
In another embodiment, Ender discloses a winding core with a bead-like ridge-valley configuration along the top and bottom of the core; and indentations along a ridge are provided to receive pins projecting from a mating valley to prevent relative rotation of adjacent cores.
Steinback, U.S. Pat. No. 3,848,310 shows spindle indentations along the inside of the hub for a flanged tape reel. Browning, U.S. Pat. No. 3,508,719 shows two sets of interlocking beads along opposite outside surfaces of a flanged tape reel. Herolzer, U.S. Pat. No. 3,696,966 discloses a rise along the inside of a bottom part of a chick carton which fits into a corresponding indentation along the bottom outside surface of a mating bottom for a like carton. Jewell et al, U.S. Pat. No. 3,153,519 shows mounting tubes for yarn packets, with interlocking parts extending between the yarn packets. Taus, U.S. Pat. No. 3,527,344 is of some, lesser interest.